The present invention relates to hydraulic systems and, more particularly, to a hydraulic system embodying a method for combining two or more hydraulic functions from operatively associated distributor valves to selectively increase fluid pressure and flow using only hydraulic switches and valves.
In hydraulic equipment, such as a knuckle boom crane or a hydraulic excavator, there may be a need for increased hydraulic flow to one of a plurality of hydraulic attachments or devices, wherein it is very expensive and often impractical to modify an existing machine to increase the fluid flow of the entire hydraulic system to supply an increased volume of hydraulic oil pressurized to said one of the plurality of attachments/devices by installing larger valves or larger diameter hoses and fittings.
Prior art combines the flow from two hydraulic pumps in a priority function configuration. The most common way to combine oil flow at the attachment uses electro/hydraulic solenoids to divert oil using electric switches and computer software. Electro/hydraulic systems require infrastructure such as wiring and contact switches to enable the oil flow to be combined. The extra wiring system needed to support the solenoids as well as the interface with the existing hydraulic system, however, is difficult and expensive. Electrical wiring and switching is also prone to breakdown in a harsh work environment.
As can be seen, there is a need for a method for combining two or more hydraulic functions at the attachment from operatively associated distributor valves for selectively increasing fluid flow using only hydraulic switches and valves. Through combining the flow of a hydraulic medium from two or more hydraulic circuits at the point of use, the present invention enables the selected attachment to benefit from the increased hydraulic flow at comparatively lower cost and effort. Furthermore, by using only hydraulic actuators and valves, the present invention is a simple cost-effective solution that can be easily retrofitted on almost any hydraulic machine to improve the hydraulic flow performance of one of a plurality of hydraulic attachments without any other modification.